Year	Percent
1990	73.468
1991	73.098
1992	72.723
1993	72.385
1994	72.047
1995	71.653
1996	70.559
1997	70.411
1998	69.621
1999	67.847
2000	66.634
2001	65.37
2002	63.847
2003	66.618
2004	65.706
2005	64.737
2006	67.553
2007	68.446
2008	69.041
2009	68.176
2010	67.07
2011	67.895
2012	68.286
2013	68.319
2014	68.903
2015	69.517
2016	70.567
2017	70.256
2018	69.871
2019	69.432
2020	68.958
2021	68.387
2022	67.778
2023	67.167
2024	66.605
2025	66.124
2026	65.677
2027	65.324
2028	65.039
2029	64.784
2030	64.532